Thermostat.



G. c. NDREWSQ I THERMOSTAT. v APPLICATION YILBD HAR. 20, 1912. y *1,131,651 Patented Mar.16,1915.

Figjn ,Pagg jpg. 5 1 1b 'i tjNlll utilised to control GEORGE v mnmosxwr.

Application lcd Huch To all whom it may concern Be it known that', GEORGE C. A Nnlmws, a citizen' of the United States', residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain` new and useullmprovements in Thermostats; and I do hereby declare the 'following to be a full, clear, and exact description of the invention such as will enable others skilled in the art 'to which it appertains to make and use the sam Y My inventionfhas for its particular object to simplify the construction and irnprove the action of temperature regulators ofthat type wherein an electric circuit hav ing contacts controlled by a thermally ex.- panded orl extended controlling element, vis the actions of a suitable motor, which, lin turn, lcontrols dampers, valves. or similar elements of a furnace or other heat producing medium.

Generally stated, the invention consists `ot the novel devices and combinations of de- `vices hereinafter described and defined in the claims. n

In the accompanying drawings which illustrate tue invention, like characters indicate like parts throughout the several/views.

Referring to the drawings, Figure 1 is a view in front elevation showing the improved temperature regulator with a thermometer attached; Fig. 2 is a view corresponding to Fig. 1 with the thermometenremoved; Fig. 3 is a rear elevation of the regulater; Fig. 4 is a horizontal section taken approximately on the line x4 w* on Fig. 3*; Fig. is a detail view in plan showinga knob or finger piece and coperating crank for adjustably setting the contacts of the regulator; Fig. 6 -is a fragmentary view in end elevation showing the upper end portion of' a thermally operated contact arm; and Fig. 7 is a fragmentary view in front eleva# tion illustrating a slightmodification of the lulcrum which supports the thermally operated contact arm.

The various parts of the regulator proper are mounted directly or indirectly upon a base or back member l, `preferably pressed sheet metal.

. is anchored the ends of a or bent into channel shape vform from thin One side of the base l is provided with a vertically extended' and outwardly projecting flange or bar 2 to which flexible steel ribbon 3. rlhis ribbon 3 is slightly bowed andthe' bow thereof will be increased by relatively high and decreased by relatively low tem- Speotcation nt Letters htent. y Patented M31-, 16, 1915,

zo, 191s. serial No.' essais.

. as is usual, in the form of screws A'NDnEWs, or mnnwous, mnu-scorn.

peratures. The said element constitutes the primary thermall operated controlling element of the reglu ator, but constitutes per se, no part of t e present invention, be ing an element well known for that purpose, and itshould be understood that so far as the broad idea of my invention is concerned, this primary controlling element may take different forms. v

Of the three contacts which control the iow'of the current through the cutinthe usual way, the numerals indicate the opposing relatively fixed contucts, and the numeral 5 indicates the relatively movable contact which works between and alternately engages the said contacts. The' so-called relatively fixed contacts 4 are, that work adjustably through binding posts 6--6, insulated from but contact carrier in the form of a segment 7, pivotally connected at 8 to the back surface of the face of the base 1. The binding posts 6 which are insulated from each other, project through a segmental slot 9 cut in the face of the base 1. The so-called relatively movable intermediate contact 5 is shown as secured to the lower end of a lever 10, which,

and lthe said element` 13 is spaced from 2a. The extreme upper end of the lever 10, above its fulcrum lugs 11, is shown as notched to form prongs, one of which is connected to the central portion of the ribbon 3 by` means o'f a light connecting rod or link 14. A very light coiled spring 15 is, as shown, connected at one end to the flange 2a, and at its other end to the lever 10 at a point below its Julcrurn lugs 11. The spring 15 keeps the knife edges of the ulcrurn lugs 1l lightly seated in the notches 12 and the said lugs afford a practically `without friction`V This makes the instrument very sensitive in its action and is, therefore, a highly important eature in a device of this kind where great accuracy and delicacy of action is required.

ln' the preferred arrangement best shown in Fig. 2, the fulcrum l'ugs 11 have their bearing edges pro3ecting. at one sdeybut in Zand 13 are all rigidly secured to Tarnsra'rnn'r oFF1oE.,-f

three-line cirsecured to an adjustable sus` 'fulcrum for the said lever which operates the modied construction illustrated in Fig. 7, the corresponding fulcrum lugs 11a have their bearing edges turned downward, and the fulcrum seats 12xiL are correspondingly positioned. Also, the fulcrumbracket 123a employed in the said modified construction is of slightly dillerent form from that shown inA Fig.2, and the spring 15, as well as the light connecting rod 14 are extended approximately horizontal, but deviate from horizontal alinement slightly, so as to exert a slight downward pressure on the fulcrum lugs which assist gravity in holding the said lugs properly seated. i

As is well understood, the temperature at which the regulator will operate either to open or close the dempers of a furnace, or will perform some similar function, will depend on the position in which the relatively fixed contacts 4 are set, in a direction from'right to left in respect to Figs. 1, 2 and 3. Hitherto, the adjustments ofv the contacts carrier 7 have been accomplished by the oscillation of the controlling knob or finger piece having a pointer coperating with the temperature scale to indicate the temperature which the controller willv operate. It has been customary however to provide the stem of such a knob with a pinion meshing with the segmental gear of the said segment 47, or-corresponding part. My invention provides an improvelment in this connecting device, whereby muchy less lostl motion, and hence, better accuracy in the setting is obtained. The setting knob 16 is shown as provided with the ,'usual pointer 17 that coperates with the temperature scale 18 marked on the lower portion of. the face of the base 1. The numeral 19 indicates a crank in the form of a disk provided' with a stem 20 pivoted in and extended through the lower portion ofthe basel and driven yinto a seat in the knob 16 with suliicient friction to` secure the said parts 16 and 19 for common oscillatory movements. A link 21 connects Yone lower lside portion-of the vibratory contact carrier 7 with an eccentricportion of the crank disk 19, so that by oscillatory movements of the knob 16, the desired adjustments of the contact carrier 7 are accomplished. Preferably, and as shown, the link 21 is formed by a short section of alight rod or heavy wire having its ends bent and passed through perforations inthe said elements 7 and 19 and upset or riveted so as to hold the said link in working position.

The numeral 22 indicates a thermometer` shown as secured to a light pressed sheet metal outer easing 23 which, in. turn, is detachabl'y'secured to the base `1 and coversv the lever v10 and certain other parts butr 4leaves the knob 16, :scale: 1B and contacts Vnation with relatively fixed contacts and a trolled contact, of a vibratory contact Aportion is shown as provided with a back- Wardly pressed flange 24 having perfor.- tions, through which, nails or screws may be passed to secure the regulator to a wallor any other suitable place.

What I claim is:

1. In a tem erature regulator, a contact lever having ife edge lcontact lugs projecting fromits opposite sides, seats for the c said lugs formed on a relatively fixed part of said regulator, a thermally actuated controller for said lever having a link connected'thereto on one side of itsfulcrum lugs,A and a spring connected to said lever on the opposite side of said fulcrumlugs, the said link and spring extending from said lever in the Isame direction and exerting a force on said lever holding the fulcrum lugs thereof seated irrespective of gravity.

2. In a temperature regulator, the combicoperating intermediate relatively movable contact, of an upright lever carrying said movable contact and provided with knife edge, fulcrum lugs seated in a relatively fixed part of said regulator, a thermally actuated expansible controlling ele-NWT' ment, a link connecting the latter to said lever close to but on one side of its fulcrum lugs, and a light coiled spring anchored at one end and connected at its other end to au said lever on the other side of its fulcrum lugs.

3. In a temperature regulator, the coxnbnation with relatively fixed contacts and a coperating intermediate therually, con- Cll 1- rier` adjustably supporting said relatively fixed contacts, an operating knob, and a link connecting an eccentric pofption of said knob to said vibratory contact carrier for adjusting said relatively fixed contacts-'m respect to the intermediate contact.

4. In a temperature regulator`,` the combi V'nation with ,fa base member, of relatively fixed contacts, a coperating, intermediate thermally actuated jcon'tact, an oscillatory contact carrier -ad'justably-supporting sald relatively fixed contacts, an operating knob, a crank disk having a stem passed through and rotatablyfseated in said'lbase and "tric,-` tionallyf driven into, said-knob, and a link having Vlaterally bent ends vpivota'lly connected tosaid contact carriuar` and.' to said crank disk.- y I Intestimcny whereof Iaix my signature 12S in presence of two witnesses.

, y Geenen c. annnsws. witnesses HARRY p. Kamm, F. D. MERCHANT. 

